The angular misalignment of a three-point supported dual-span rotor system is discussed. Vibration measurement for coupling misalignment is taken in this paper by using the model test rig, and the rotor vibration response characteristics with different misalignment quantities and different rotating speed are compared. Based on the finite element method, researches on the three-point supported dual-span rotor system are made, and then the simulation and experimental results are compared. Both the simulation and the measurement are compared to show the features. The results show that the amplitudes of the misaligned rotor vary with rotating speeds and misalignment angles, and the center orbits of the misaligned rotor change into ellipses with the increase of misalignment, together with double harmonic responses.